| A study on the computer network security for banks is significantly important to the whole financial information security. This thesis is based on the author's work in the network-rebuilding project of the Comprehensive Business System (CBS) of the Agricultural Development Bank of China (ADBC). Considering the already-running network conditions, and based on the security risk analyses and assessment, referring to the dynamic information security model, it frames out the sound network security policy for the CBS as well as the hierarchy security system according to the policy. With the in-phase built-in deployment of the network-rebuilding project for the CBS, the network security system has got good practical results. It's believed that this paper will be an important instructive reference for the future development of ADBC's information security system. |